Atomic Test And Set Of Disk Block Returned False For Equality [updated] Jun 2026

If you are seeing this error in your logs, consider these steps from industry guides:

If a node gets false for equality on its own disk block: If you are seeing this error in your

while (atomic_test_and_set(disk_block, expected, new) == false) // Another node won the race current_leader = read_leader_from_disk(); if (current_leader == myself) // Possibly stale cache, re-read block invalidate_disk_cache(); else backoff_and_retry(); re-read block invalidate_disk_cache()

Imagine a cluster with two nodes both trying to claim ownership of a shared LUN (Logical Unit Number). Each node issues: when it occurs unexpectedly

The error is not a bug—it is a safety mechanism. It signals that your storage system correctly prevented a conflicting write in a concurrent environment. However, when it occurs unexpectedly, it indicates deeper issues: stale caches, lingering reservations, misaligned architectures, or hardware faults.